Butadiene (C4H6), the coefficients for the linear combination of atomic orbitals for the two lowest energy π-MOs are:
Normalised Coefficients MO
Atom 1
Atom 2
Atom 3
Atom 4
Wavefunction 2:
+0.6015
+0.3717
-0.3717
-0.6015
Wavefunction 1:
+0.3717
+0.6015
+0.6015
+0.3717
(i) Predict the coefficients at each atom for the two highest energy π-MOs (wavefunctions 3 & 4). Justify your solution using diagrams.
(ii) Calculate the total π-electron densities on atoms 1, 2, 3, and 4.
(iii) Calculate the total p-bond order between atoms 1-2, 2-3, and 3-4.
(iv) Estimate the total σ- and π-bond orders between atoms 1-2, 2-3, and 3-4.
(v) How does (iv) relate to the traditional representation of butadiene with a double-single-double bond structure.